Registering renewable plug fuses



Dec. 24, 1929. J. P. GILLlAM REGISTERING RENEWABLE PLUG FUSS v Filed Nov. 22. 1926 1 l a @W kv Patented Dec. 24, 1929 JAMES 1". GILLIAM, OF LOS ANGELES, CALIFORNIA REGISTERING RENEWABLE PLUG FUSES Application led November 22, 1926.

This invention relates to electric fuses and especially to the class of fuses which are adapted for use in fuse boxes and the like.

f An object of this invention is to provide a renewable plug fuse which has thereon indicating means in order that one may determine when the fuse has been blown without l5 able, which is not likely to get out of order and which may be placed on the market for a nominal sum and which well performs the purpose for which it is intended. e l Vith the foregoing and other objects in p View which will be made manifest in the following detailed description and .specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention,

r wherein Figure 1 is a perspective view of my renewable plug fuse, a portion being broken away to reveal the novel catch member which holdsl the parts of the fuse in locked relationship,

Fig. 2 is a horizontal sectional view, the plane of section being taken along the lines 2 2 of Fig. 3, in the direction of the arrows, Fig.f3 is a vertical sectional view taken longitudinally through my plug fuse showing the same in assembled relation with the fuse intact on the hangers,

Fig. 4 is a side view of my plug `fuse showing the sheath or protective contact member removed and showing the fuse intact upon the hangers, and

Fig. 5 is a view similar to Fig. 3 showing the positions the various parts of my device assume when the fuse has been blown out.

Referring to the accompanying drawings wherein similar reference characters designatesimilar parts throughout, my improved renewable fuse comprises a hollow cylindrical body portion 1 having a head 2 and a de- I pending portion 3.' The bore of the body portion 1 within the head 2;, is of greater Serial No. 149,929.

diameter than that part of the bore with-in the depending portiony 8, these two portions of the bore being separated by an internal annular shoulder 4.-. A pair of apertures 5 and 6 extend through the wall f the depending portion 3 adjacent the top and bottom thereof respectively, as well as a vertically elongated aperture 7. A slidable button having ai non-conductive top 8 with an annular side 9 threadedly engaged thereon, is disposed within the cylindrical member and has an annular iange 10.y vA coil spring C is disposed between this annular lange and the internal [shoulder 4, and tends to normally hold the button in the position shown in Fig. 5 with the annular side wall 9 exposed. This button is designated in its entirety at 11, and may be formed of any suitable conductive material. y

Indicated at 12 and 13 are a plurality of studs extending from the button through the apertures 7 and 5 respectively. The stud 12 which is vertically slidable within its aperture 7 to permit movement of the button 11,

serves as a contact member and forms a portion of an electrical connection between the threaded sheath 14 and the button. The other stud 13 forms a han-ger for one end of the fuse 15 and the other end of the fuse is disposed over a similar stud 16 extending through the aperture 6 into a contact plug 17 which is disposed in the lower end of the cylindrical member.

The threaded sheath 14 is removably fitted upon the depending portion V3 of the body member 1, and is provided with screw threads 19 having an outercovering 2O of suitable conductive material. Electrical connection between the covering 2O and the button 11 is established when the button 11 is depressed by means ofa contact member 22 extending from the covering 2O through the wall of the sheath 14 in position to engage the outer end of the stud 12. `When the button is in thel position shown in Fig. `5 however, the stud 12 and contact 22 are out of engagement, break-v ing the electrical connection between the covering 2O and button 11.

A slot 21 in the bore of the sheath,` and a flattened. portion 21 upon the depending por tion 3 in register with each other, provide a space for the reception of the fuse element 15 and the outer ends of the studs 13 and 16, it being understood that the fuse element 15 normally holds the button 11 retracted against the action of the spring C. Proper positioning of the sheath 14 upon the body 1 to bring the slot 2l and flattened portion 2l as well as the contact 22 and stud 12 into alignment, is assured by a vertically extending pin P rigid with the sheath 1-1 in position to seat within a complementary socket in the head 2 of the body 1, preventing relative rotation of the two members.

Means are also provided for releasably locking the two members against relative longitudinal displacement.

A pin 23 is provided on the sheath la and extends into an aperture 24.- in the body portion 1. This projection forms one element of a locking member which serves to hold the sheath and body portion in locked position. A screw 26 threaded upwards into the head 2 provides a pintle on which is pivoted a latch member 27 having a thumb piece 28 accessible from the exterior of the head 2 and a coil spring 29, under compression between the button 28 and the head 2 normally holds the latch member engaged upon the pin 23 to lock the sheath 14 to the body 1.

The operation of my device is as follows: `When it is desired to place a fuse element on the hangers 13 and 16, the sheath 14 should lirst be removed by disengaging the latch 27 from the pin 23, after which it is necessary to depress the button 11 against the tension of the coil spring C so that the distance between the hangers 13 and 16 is sufficiently small to accommodate the fuse element 15. The fuse element is then strung between the two hangers and held thereon under tension by means of the coil spring C. This fuse element makes a positive electrical connection between the plug 17 and 'the threaded sheath 14. Should at any time the electrical load be so great as to rupture the fuse element, the button 11 would fly outwardly of the cylinder, thereby exposing the annular side wall 9. This side wall 9 is preferably painted white in order that one may more readily see it. For example, when a series of these fuses are employed in a fuse box which is located in the cellar of a building or some similar dark place, and one of the fuses should happen to blow in this box, it would not be necessary to remove all or any of the fuses to determine which fuse is the faulty one. The person wishing to replace the proper fuse would merely glance at the entire set of fuses until he discovered the one which had the white side wall 9 exposed, thus indicating that the fuse had blown.

In fuses which embody the principle of my invention it is not necessary, as is the case with ordinary fuses, to unscrew the socket member 18 from the fuse socket. The thumb piece 28 may be depressed, thereby releasing the latch member 27 from the pin 23. This permits the cylindrical body member to be withdrawn from the sleeve 18, thereby exposing the hangers 13 and 16 in order that a new fuse element 15 may be applied.

As shown in the drawings, my button is preferably hollow and I contemplate using the space therein as a storage compartment for fuse elements. Access thereto may be had by unscrewing the cap or insulating member 8.

It is obvious then that I have provided a renewable fuse, the initial cost of which is slightly greater than the ordinary type of non-renewable fuse now in common use, but which pays for its installation within a very short time by Virtue of the fact that the renewable fuse element 15 is very inexpensive and may be sold with my fuse retaining member.

It will be understood that various changes in the detail of construction may be made without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. An electric fuse comprising a hollow cylindrical. body portion having an internal annular shoulder and a plurality of longitudinal apertures in the wall thereof, a slid able button or" conductive material in one end of said body portion having an annular flange thereon, a coil spring disposed between said flange and shoulder, studs on said button ex tending through said apertures, a plug of conductive material in the other end of said body portion having a stud extending through another of said apertures, one of said first inentioned and said last mentioned studs forming in combination a hanger for a fuse element.

2. An electric fuse element comprising in combination a body member and a sleeve member, a plug in said body member, a button in said body member, said button form ing an electric contact with said sleeve member, studs in said plug and in said button, said button being normally urged from said plug, and means comprising a fuse element connecting said studs for holding said button against its normal tendency.

3. An electric fuse comprising a body portion having an internal annular shoulder and a plurality of longitudinal apertures in the walls thereof, a slidable button of conductive material in one end of said body portion having an annular flange thereon, a coil spring disposed between said flange and shoulder, studs on said button extending through said apertures, a plug of conductive material in the other end of said body having a stud extending through another of said apertures, one of said first mentioned and last mentioned studs forming in combination a hanger for a fuse element, and indicating means on said button whereby the condition of said fuse element may be determined.

4. An electric fuse comprising a body portion, an indicating button slidable within an aperture in said body, means urging said button outwards of said aperture, a contact plug secured to the other end of said body portion, a threaded sheath of conducting material slidably receivable about the plug end of said body and in electrical communica tion with said button, a fusible member under tension between said button and plug and adapted to establish electrical communication therebetween, said fusiblemember being disposed in a recess between said sheath and body, a pin extending from said sheath, a latch member pivoted to said body, and a spring urging said latch member into releasable engagement with said pin.

5. An electric fusecomprising a body portion, an indicating button slidable within an aperture in said body, means urging said button outwards of said aperture, a contact plug secured to the other end of said body portion, a threaded sheath of conducting material slidably receivable about the plug end of said body and in electrical communication with said button, a fusible member under tension between said button and plug and adapted to establish electrical communication therebetween, said fusible member being disposed in a recess between said sheath and body, a pin extending from said sheath, a latch member pivoted to said body, a spring urging said latch member into releasable engagement with said pin, and a thumb piece accessible from the exterior of said body for releasing said latch member to permit removal of said body from said sheath.

In testimony whereof I havel signed my name to this specification.

J. PQ GILLIAMi 

